Since the clinical trial began in 2002, 5,145 volunteers with type 2 diabetes who were 45-76 years of age and overweight or obese (body mass index > 25 kg/m2) have been recruited and enrolled in either the intensive lifestyle intervention (ILI) program or the diabetes support and education (DSE) program. The Diabetes Epidemiology and Clinical Research Section clinics enrolled 244 of these participants. The study has reported success in achieving and maintaining weight loss in the ILI group, while there was little weight loss on average in the DSE group. During the first four years after enrollment, the average weight losses were 6.2% in the ILI group and 0.9% in the DSE group. This successful weight loss means that it will be possible, at the end of the study, to determine if weight loss has long-term health benefits in adults with type 2 diabetes. The study continues these two interventions and outcome assessments so that the primary study questions can be answered in 2015. We are, therefore, making outstanding progress in delivering the interventions and following participants in order to answer the primary health outcomes questions described in the protocol.